1. Field of the Invention
The present invention relates to an image processing rejecting document, and more particularly to a document specially printed in order to prevent exact copies of a color document, such as a bank bill and marketable securities. Further, the present invention relates to an image processing system with an illicit use check function for preventing exact copies of a color original document, such as the specially printed document, bank bill, and marketable securities.
2. Description of the Related Art
The copy rejecting technique of a conventional copying machine is categorized into two types of techniques; a first technique uses an original document which contains features that do not result in a normal copy by the machine and a second technique in which the copying machine detects an original document that is not to be copied by the image reading/detecting unit and rejects a normal copy of such a document.
The first technique using the normal copy rejecting document comes in many varieties. A first example of this technique applies metal powder to a document. The copying machine reproduces images on the document other than images based on the metal powder by a document illuminating lamp. Another example is based on Moire or holography caused by combining a background pattern of a document print image and a mesh at the time of copying. An additional example uses ink of fluorescence which provides an unclear copy image. A further example uses blue ink which can be little reproduced by the copying machine using a selenium photoreceptor.
In the second technique detecting a document not to be copied in the image reading/detecting stage, the machine checks whether or not a document to be copied belongs to those documents that are allowed to be copied, in that stage. The checking operation is made by comparing the read image data with basic data stored in a memory. If the document is not to be copied, the machine does not operate for copying or produces the output image left unfixed or an abnormal output image.
However, the illicit use check techniques as mentioned above are not matured to the practical use, and still have problems to be solved. Accordingly, those techniques are not widely used. Further, the technique using the image reading/detecting unit indispensably uses a memory of a large memory capacity for storing the basic data of specific documents, and also requires comparing means for comparing the read or input image data with the basic data in order to check the input image data. The use of such a large memory and comparing means increases the cost to manufacture.